function hideElement(elementID) {
  document.getElementById(elementID).style.display = 'none';
}

function showElement(elementID) {
  document.getElementById(elementID).style.display = 'block';
}

function toggleSection(sectionID) {
  if (document.getElementById(sectionID).style.display == '')
    document.getElementById(sectionID).style.display = 'none';
  if (document.getElementById(sectionID).style.display != 'none')
    hideSection(sectionID)
  else
    showSection(sectionID);
}

function hideSection(sectionID) {
  hideElement(sectionID);
  document.getElementById(sectionID + 'Image').src = 'expand.gif';
}

function showSection(sectionID) {
  showElement(sectionID);
  document.getElementById(sectionID + 'Image').src = 'collapse.gif';
}

function getStringBefore(source, find) {
  var s = String(source);
  return s.substring(0, s.indexOf('#'));
}

function getStringAfter(source, find) {
  var s = String(source);
  if (s.indexOf(find) == -1) return "";
  return s.substring(s.indexOf(find) + find.length, s.length);
}

function opacity(id, opacStart, opacEnd, millisec) {
	//speed for each frame
	var speed = Math.round(millisec / 100);
	var timer = 0;

	//determine the direction for the blending, if start and end are the same nothing happens
	if(opacStart > opacEnd) {
		for(i = opacStart; i >= opacEnd; i--) {
			setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
			timer++;
		}
	} else if(opacStart < opacEnd) {
		for(i = opacStart; i <= opacEnd; i++)
			{
			setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
			timer++;
		}
	}
}

//change the opacity for different browsers
function changeOpac(opacity, id) {
	var object = document.getElementById(id).style; 
	object.opacity = (opacity / 100);
	object.MozOpacity = (opacity / 100);
	object.KhtmlOpacity = (opacity / 100);
	object.filter = "alpha(opacity=" + opacity + ")";
}

function shiftOpacity(id, millisec) {
	//if an element is invisible, make it visible, else make it ivisible
	if(document.getElementById(id).style.opacity == 0) {
		opacity(id, 0, 100, millisec);
	} else {
		opacity(id, 100, 0, millisec);
	}
}

function blendimage(divid, imageid, imagefile, millisec) {
	var speed = Math.round(millisec / 100);
	var timer = 0;
	
	//set the current image as background
	var image = document.getElementById(imageid);
	var div = document.getElementById(divid); 
	div.style.backgroundImage = "url(" + image.src + ")";
	//div.style.width = image.width;
	//div.style.height = image.height;
	
	//make image transparent
	changeOpac(0, imageid);
	
	//make new image
	image.src = imagefile;

  // Add padding to the image so it is the correct height
  //image.style.paddingBottom = (div.height - image.height ) + 'px'


	//fade in image
	for(i = 0; i <= 100; i++) {
		setTimeout("changeOpac(" + i + ",'" + imageid + "')",(timer * speed));
		timer++;
	}
}

function currentOpac(id, opacEnd, millisec) {
	//standard opacity is 100
	var currentOpac = 100;
	
	//if the element has an opacity set, get it
	if(document.getElementById(id).style.opacity < 100) {
		currentOpac = document.getElementById(id).style.opacity * 100;
	}

	//call for the function that changes the opacity
	opacity(id, currentOpac, opacEnd, millisec)
}